Hermetic compressor

ABSTRACT

Stopper contains abutment section at a position that corresponds to arm section so as to keep a clearance from arm section of discharge reed. The structure above allows discharge reed to have two-stage spring characteristics; discharge reed exhibits a weaker springiness until arm section abuts against abutment section, and then exhibits a stronger springiness after the abutment. Employing the discharge reed having the two-stage characteristics allows discharge valve unit to easily open and quickly close without delay. Such structured hermetic compressor enhances energy efficiency, preventing degradation in refrigeration performance.

TECHNICAL FIELD

The present invention relates to improvement in a discharge valve unit of a hermetic compressor employed mainly for a refrigerating device.

BACKGROUND ART

Conventionally, some hermetic compressors contain a discharge valve unit that not only reduces noise in operation, but also improves energy efficiency by decreasing loss in opening and closing movements of a discharge reed. For example, Japanese Patent Unexamined Publication No. H10-318146 discloses a structure of the aforementioned compressors.

A conventional hermetic compressor will be described hereinafter with reference to the accompanying drawings.

FIG. 13 is a section view of a conventional hermetic compressor. FIG. 14 is a plan view of a conventional hermetic compressor. FIG. 15 is an exploded view of a discharge valve unit of a conventional hermetic compressor. FIG. 16 is a side section view of a discharge valve unit of a conventional hermetic compressor. FIG. 17 shows spring characteristics of a discharge valve unit of a conventional hermetic compressor.

In FIGS. 13 through 17, hermetic container 1 has discharge pipe 2 and suction pipe 3 that are connected to a cooling system (not shown). Hermetic container 1 retains oil 4 in the bottom and accommodates electrical driving element 7, which is formed of stator 5 and rotator 6, and compression mechanism 8 driven by element 7. The interior of hermetic container 1 is filled with refrigerant 9.

Next will be described the main structure of compression mechanism 8.

Cylinder 10 contains compression chamber 11, which is substantially formed into a cylindrical shape, and bearing 12. Discharge valve unit 14 is disposed on valve plate 13 on the side opposite to cylinder 10 so as to seal compression chamber 11. Valve plate 13 is covered with head 15.

Suction muffler 16 is formed of tail pipe 17 and a sound-deadening space (not shown). Having an opening in container 1, tail pipe 17 is a suction passage for refrigerant gas. One end of suction muffler 16 has communication with the inside of compression chamber 11.

Crankshaft 18, which has main shaft section 19 and eccentric section 20, is held by bearing 12 of cylinder 10. Rotator 6 is press-fitted around crankshaft 18. Piston 21 is inserted in cylinder 10 so as to have a reciprocal sliding movement. Connecting rod 22 connects between eccentric section 20 and piston 21.

Next will be described discharge valve unit 14 of compression mechanism 8.

Valve plate 13 contains discharge hole 23 connected to cylinder 10, and valve seat section 24 on the side opposite to cylinder 10. Valve seat section 24 is formed so as to surround discharge hole 23.

Discharge reed 25, which is made of leaf spring material, contains opening/closing section 26 for opening and closing valve seat section 24.

Head 15 contains discharge chamber 27 for accommodating discharge valve unit 14 therein. Stopper 28, which restrains opening of discharge reed 25, is integrally formed on head 15. Valve plate 13, discharge reed 25, and head 15 are disposed in the order named and bolted with bolt 29 on the side of cylinder 10.

Now will be described the workings of such structured hermetic compressor.

Feeding electric power to electrical driving element 7 rotates rotator 6, by which crankshaft 18 rotates. In the rotation, eccentric rotating movement of eccentric section 20 is transmitted to piston 21 via connecting rod 22. Receiving the movement, piston 21 has a reciprocal movement in compression chamber 11.

As piston 21 reciprocally moves, refrigerant 9 in hermetic container 1 is fed through suction muffler 16 into compression chamber 11. Refrigerant 9 with low pressure flows through the cooling system (not shown) and suction pipe 3 into hermetic container 1. Refrigerant 9 suctioned into compression chamber 11 is compressed by the movement of piston 21 and then delivered into discharge chamber 27 of head 15 via discharge valve unit 14 of valve plate 13. High-pressure gas of refrigerant 9 delivered to discharge chamber 27 of head 15 is further delivered to the cooling system (not shown) via discharge pipe 2.

In the refrigerant discharge above, discharge valve unit 14 carries out predetermined opening/closing operation, and unit 14 provides fluid communication via discharge hole 23 between compression chamber 11 and discharge chamber 27 of head 15 by opening discharge reed 25, and unit 14 closes off communication between compression chamber 11 and discharge chamber 27 of head 15 by closing discharge reed 25.

According to the conventional structure above, however, discharge reed 25 exhibits a certain springiness until meeting with stopper 28.

Here will be given detailed description on the working of discharge valve unit 14.

When a difference in pressure between cylinder 10 and discharge chamber 27 of head 15 becomes greater, compressed high-pressure gas of refrigerant 9 pushes up opening/closing section 26 and contacts it with stopper 28, so that discharge reed 25 of discharge valve unit 14 opens.

On the other hand, when the difference in pressure between cylinder 10 and discharge chamber 27 of head 15 becomes smaller, opening/closing section 26 of discharge reed 25 moves away from stopper 28 by restoring force against elastic deformation and returns its initial position to seal valve seat section 24. Until making a contact with stopper 28, discharge reed 25 exhibits a certain springiness with no deviation point, as shown in FIG. 17. Providing discharge reed 25 with a smaller springiness allows discharge reed 25 to have an opening according to a flow amount of the gas until discharge reed 25 abuts against stopper 28. Besides, by virtue of the smaller springiness, discharge reed 25 is easily open, and accordingly an excessively compressed condition in the compression chamber can be reduced. However, in closing movement, discharge reed 25 has a delay in closing due to return at a slow speed. This invites a backflow of high-pressure refrigerant 9 into compression chamber 11, thereby reducing substantial displacement volume by piston 21 and therefore resulting in poor refrigeration.

On the other hand, providing discharge reed 25 with a larger springiness eliminates a delay in closing. However, the larger springiness inconveniently invites an excessively compressed condition in opening movement due to the strengthened spring force.

DISCLOSURE OF THE INVENTION

The present invention addresses the problem above. The present invention therefore provides a hermetic compressor with high energy efficiency by virtue of improved discharge reed 25 that easily opens and quickly closes without delay.

According to the hermetic compressor of the present invention, an abutment section is disposed on a stopper at a position corresponding to an arm of the discharge reed so as to keep a clearance from the arm. The arm of the discharge reed exhibits two-stage springiness: a smaller springiness until abutment against the abutment section, and a larger springiness after the abutment.

According to the hermetic compressor of the present invention, the discharge valve unit provides an easy opening and a quick closing without delay by virtue of the two-stage springiness. The aforementioned structure allows a hermetic compressor to have less excessive compression and to have high performance in refrigeration. That is, the hermetic compressor with high energy-efficiency is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section view of a hermetic compressor in accordance with a first exemplary embodiment of the present invention.

FIG. 2 is a plan view of the hermetic compressor in accordance with the first exemplary embodiment.

FIG. 3 is an exploded view of a discharge valve unit of the hermetic compressor in accordance with the first exemplary embodiment.

FIG. 4 is a side section view of the discharge valve unit of the hermetic compressor at a middle stage of opening movement in accordance with the first exemplary embodiment.

FIG. 5 is a side section view of the discharge valve unit of the hermetic compressor at a final stage of opening movement in accordance with the first exemplary embodiment.

FIG. 6 shows spring characteristics of the discharge valve unit of the hermetic compressor in accordance with the first exemplary embodiment.

FIG. 7 is a section view of a hermetic compressor in accordance with a second exemplary embodiment of the present invention.

FIG. 8 is a plan view of the hermetic compressor in accordance with the second exemplary embodiment.

FIG. 9 is an exploded view of a discharge valve unit of the hermetic compressor in accordance with the second exemplary embodiment.

FIG. 10 is a side section view of the discharge valve unit of the hermetic compressor at a middle stage of opening movement in accordance with the second exemplary embodiment.

FIG. 11 is a side section view of the discharge valve unit of the hermetic compressor at a final stage of opening movement in accordance with the second exemplary embodiment.

FIG. 12 shows spring characteristics of the discharge valve unit of the hermetic compressor in accordance with the second exemplary embodiment.

FIG. 13 is a section view of a conventional hermetic compressor.

FIG. 14 is a plan view of the conventional hermetic compressor.

FIG. 15 is an exploded view of a discharge valve unit of the conventional hermetic compressor.

FIG. 16 is a side section view of the discharge valve unit of the conventional hermetic compressor.

FIG. 17 shows spring characteristics of the discharge valve unit of the conventional hermetic compressor.

DETAILED DESCRIPTION OF CARRYING OUT OF THE INVENTION First Exemplary Embodiment

FIG. 1 is a section view of a hermetic compressor in accordance with a first exemplary embodiment of the present invention. FIG. 2 is a plan view of the hermetic compressor in accordance with the first exemplary embodiment. FIG. 3 is an exploded view of a discharge valve unit of the hermetic compressor in accordance with the first exemplary embodiment. FIG. 4 is a side section view of the discharge valve unit of the hermetic compressor at a middle stage of opening movement in accordance with the first exemplary embodiment. FIG. 5 is a side section view of the discharge valve unit of the hermetic compressor at a final stage of opening movement in accordance with the first exemplary embodiment. FIG. 6 shows spring characteristics of the discharge valve unit of the hermetic compressor in accordance with the first exemplary embodiment.

In FIGS. 1 through 6, hermetic container 101 has discharge pipe 102 and suction pipe 103 that are connected to a cooling system (not shown). Hermetic container 101 retains oil 104 in the bottom and accommodates electrical driving element 107, which is formed of stator 105 and rotator 106, and compression mechanism 108 driven by element 107. The interior of hermetic container 101 is filled with refrigerant 109. Refrigerant 109 is, for example, R134a, or R600a that is a natural refrigerant.

The main structure of compression mechanism 108 will be described hereinafter.

Cylinder 110 contains compression chamber 111, which is substantially formed into a cylindrical shape, and bearing 112. Discharge valve unit 114 is disposed on valve plate 113 on the side opposite to cylinder 110 so as to seal compression chamber 111. Head 116 has discharge chamber 115 in which discharge valve unit 114 is accommodated. Valve plate 113 is covered with head 116.

Suction muffler 117 is formed of tail pipe 118 and a sound-deadening space (not shown). Having an opening in hermetic container 101, tail pipe 118 is a suction passage for refrigerant gas. One end of suction muffler 117 has communication with the inside of compression chamber 111.

Crankshaft 119, which has main shaft section 120 and eccentric section 121, is held by bearing 112 of cylinder 110. Rotator 106 is press-fitted around crankshaft 119. Piston 122 is inserted in cylinder 110 so as to have a reciprocal sliding movement. Connecting rod 123 connects between eccentric section 121 and piston 122.

Next will be described discharge valve unit 114 of compression mechanism 108.

Valve plate 113 contains discharge hole 124 and valve seat section 125 on the side opposite to cylinder 110. Valve seat section 125 is formed so as to surround discharge hole 124.

Discharge reed 126, which is made of leaf spring material, contains opening/closing section 129 for opening and closing valve seat section 125, and arm 130.

Stopper 127 restrains opening of discharge reed 126. Stopper 127 contains abutment section 131 and restraint section 132. Abutment section 131 is disposed at a position corresponding to arm 130 so as to keep a clearance from arm 130. Restraint section 132 is disposed at a position corresponding to opening/closing section 129 so as to keep a clearance from arm 130. This clearance is larger than that between abutment section 131 and arm 130.

Discharge reed 126 and stopper 127 are disposed in the order named and riveted by rivet 133 with valve plate 113.

Now will be described the workings of such structured hermetic compressor and effects obtained by the compressor.

Feeding electric power to electrical driving element 107 rotates rotator 106, by which crankshaft 119 rotates. In the rotation, eccentric rotating movement of eccentric section 121 is transmitted to piston 122 via connecting rod 123. Receiving the movement, piston 122 has a reciprocal movement in compression chamber 111.

As piston 122 reciprocally moves, refrigerant 109 in hermetic container 101 is fed through suction muffler 117 into compression chamber 111. Refrigerant 109 with low pressure flows through the cooling system (not shown) and suction pipe 103 into hermetic container 101. Refrigerant 109 suctioned into compression chamber 111 is compressed by the movement of piston 122 and then delivered into discharge chamber 115 via discharge valve unit 114 of valve plate 113. High-pressure gas of refrigerant 109 delivered to discharge chamber 115 is further delivered to the cooling system (not shown) via discharge pipe 102.

In the refrigerant discharge above, discharge valve unit 114 carries out predetermined opening/closing operation; unit 114 provides fluid communication via discharge hole 124 between compression chamber 111 and head 116 by opening discharge reed 126, and unit 114 closes off communication between compression chamber 111 and head 116 by closing discharge reed 126.

Until discharge reed 126 abuts against abutment section 131 of stopper 127, reaction force of the high-pressure gas of refrigerant 109 allows discharge reed 126 to be kept open. Discharge reed 126 exhibits a certain springiness with no deviation point until abutting against abutment section 131 of stopper 126. Keeping the spring constant until the abutment (i.e., the first-stage spring constant) to a low level weakens the springiness of discharge reed 126, thereby discharge reed 126 easily opens.

After the abutment of discharge reed 126 against abutment section 131 of stopper 127, discharge reed 126 further bends on the abutting position as a fulcrum. The spring constant after the abutment (i.e., the second-stage spring constant) is greater than the first-stage spring constant. As a result, after abutment against abutment section 131, an increased springiness of discharge reed 126 generates a strong reaction force, which accelerates the closing speed of discharge reed 126.

As described above, discharge reed 126 exhibits two-stage spring characteristics—a weaker springiness until arm 130 of discharge reed 126 abuts against abutment section 131, and a stronger springiness after the abutment. This allows discharge valve unit 114 to easily open and to quickly close at a fast speed. By virtue of such an improved discharge valve unit, a hermetic compressor having less excessive compression and high refrigeration performance, that is, having high energy-efficiency is obtained.

Although the first exemplary embodiment introduces a structure having a single abutment section, it is not limited thereto. Forming a plurality of abutment sections 131 allows discharge reed 126 to have more preferable springiness in opening movement and reaction force. This provides a hermetic compressor having further less excessive compression and high refrigeration performance, that is, having further high energy-efficiency.

After abutting against abutment section 131 of stopper 127, discharge reed 126 further bends and reaches restraint section 132. Because discharge reed 126 contacts with restraint section 132 with a section close to the tip, discharge reed 126 is unlikely to have further bend. This can suppress internal stress due to the deformation of discharge reed 126. Even under condition where a large deformation is expected in discharge reed 126 due to liquid compression or compression of highly concentrated refrigerant gas, an excessive increase in the internal stress in discharge reed 126 is prevented. This protects discharge reed 126 from breakage, providing the structure with high reliability.

If liquid compression occurs, a heavy load is imposed on opening/closing section 129 of discharge reed 126 due to the use of highly concentrated liquid refrigerant, opening/closing section 129 is hardly pushed against the abutment surface of stopper 127. However, stopper 127 is securely fixed with valve plate 113 by rivet 133. Such a fixed connection (with no worry about coming-off of stopper 127) provides the hermetic compressor with high reliability.

Abutment against stopper 127 gives an impact to discharge reed 126. To ease the impact, the abutment surface of stopper 127 has a rounded finish. It is intended that the stress applied to discharge reed 126 has little effect on the quality and reliability of discharge valve unit 114.

Second Exemplary Embodiment

FIG. 7 is a section view of a hermetic compressor in accordance with a second exemplary embodiment of the present invention. FIG. 8 is a plan view of the hermetic compressor in accordance with the second exemplary embodiment. FIG. 9 is an exploded view of a discharge valve unit of the hermetic compressor in accordance with the second exemplary embodiment. FIG. 10 is a side section view of the discharge valve unit of the hermetic compressor at a middle stage of opening movement in accordance with the second exemplary embodiment. FIG. 11 is a side section view of the discharge valve unit of the hermetic compressor at a final stage of opening movement in accordance with the second exemplary embodiment. FIG. 12 shows spring characteristics of the discharge valve unit of the hermetic compressor in accordance with the second exemplary embodiment.

In FIGS. 7 through 12, hermetic container 201 has discharge pipe 202 and suction pipe 203 that are connected to a cooling system (not shown). Hermetic container 201 retains oil 204 in the bottom and accommodates electrical driving element 207, which is formed of stator 205 and rotator 206, and compression mechanism 208 driven by element 207. The interior of hermetic container 201 is filled with refrigerant 209. Refrigerant 209 is, for example, R134a, or R600a that is a natural refrigerant.

The main structure of compression mechanism 208 will be described hereinafter.

Cylinder 210 contains compression chamber 211, which is substantially formed into a cylindrical shape, and bearing 212. Discharge valve unit 214 is disposed on valve plate 213 on the side opposite to cylinder 210 so as to seal compression chamber 211. Head 216 has discharge chamber 215 in which discharge valve unit 214 is accommodated. Valve plate 213 is covered with head 216.

Suction muffler 217 is formed of tail pipe 218 and a sound-deadening space (not shown). Having an opening in container 201, tail pipe 218 is a suction passage for refrigerant gas. One end of suction muffler 217 has communication with the inside of compression chamber 211.

Crankshaft 219, which has main shaft section 220 and eccentric section 221, is held by bearing 212 of cylinder 210. Rotator 206 is press-fitted around crankshaft 219. Piston 222 is inserted in cylinder 210 so as to have a reciprocal sliding movement. Connecting rod 223 connects between eccentric section 221 and piston 222.

Next will be described discharge valve unit 214 of compression mechanism 208.

Valve plate 213 contains discharge hole 224 and valve seat section 225 on the side opposite to cylinder 210. Valve seat section 225 is formed so as to surround discharge hole 224.

Discharge reed 226, which is made of leaf spring material with a shape of tongue, contains opening/closing section 229 for opening and closing valve seat section 225, and arm 230.

Stopper 227, which restrains opening of discharge reed 226, is integrally formed with head 216. Stopper 227 contains abutment section 231 and restraint section 232. Abutment section 231 is disposed at a position corresponding to arm 230 so as to keep a clearance from arm 230. Restraint section 232 is disposed at a position corresponding to opening/closing section 229 so as to keep a clearance from arm 230. This clearance is larger than that between abutment section 231 and arm 230. Cap 233 is press-fitted with the abutment surfaces, of abutment section 231 and restraint section 232. Cap 233 is made of tetrafluoroethylene, which is a solid lubricating material with non-adhesion, refrigerant-resistance, chemical stability, and heat-resistance.

Valve plate 213, discharge reed 226 and head 216 are disposed in the order named and bolted with bolt 234 on the side of cylinder 210.

Now will be described the workings of such structured hermetic compressor and effects obtained by the compressor.

Feeding electric power to electrical driving element 207 rotates rotator 206, by which crankshaft 219 rotates. In the rotation, eccentric rotating movement of eccentric section 221 is transmitted to piston 222 via connecting rod 223. Receiving the movement, piston 222 has a reciprocal movement in compression chamber 211.

As piston 222 reciprocally moves, refrigerant 209 in hermetic container 201 is fed through suction muffler 217 into compression chamber 211. At the same time, refrigerant 209 with low pressure flows through the cooling system (not shown) and suction pipe 203 into hermetic container 201. Refrigerant 209 suctioned into compression chamber 211 is compressed and then delivered into head 216 via discharge valve unit 214 of valve plate 213. High-pressure gas of refrigerant 209 delivered to discharge chamber 215 is further delivered to the cooling system (not shown) via discharge pipe 202.

In the refrigerant discharge above, discharge valve unit 214 carries out predetermined opening/closing operation; unit 214 provides fluid communication via discharge hole 224 between compression chamber 211 and head 216 by opening discharge reed 226, and unit 214 closes off communication between compression chamber 211 and head 216 by closing discharge reed 226.

Until discharge reed 226 abuts against abutment section 231 of stopper 227, reaction force of the high-pressure gas of refrigerant 209 allows discharge reed 226 to be kept open. Discharge reed 226 exhibits a certain springiness with no deviation point until abutting against abutment section 231 of stopper 227. Keeping the spring constant until the abutment (i.e., the first-stage spring constant) to a low level weakens the springiness of discharge reed 226, thereby discharge reed 226 easily opens.

After the abutment of discharge reed 226 against abutment section 231 of stopper 227, discharge reed 226 further bends on the abutting position as a fulcrum. The spring constant after the abutment (i.e., the second-stage spring constant) is greater than the first-stage spring constant. As a result, after abutment against abutment section 231, an increased springiness of discharge reed 226 generates a strong reaction force, which accelerates the closing speed of discharge reed 226.

As described above, discharge reed 226 exhibits two-stage spring characteristics—a weaker springiness until arm 230 of discharge reed 226 abuts against abutment section 231, and a stronger springiness after the abutment. This allows discharge valve unit 214 to easily open and to quickly close at a fast speed. By virtue of such an improved discharge valve unit, a hermetic compressor having less excessive compression and high refrigeration performance, that is, having high energy-efficiency is obtained.

Although the second exemplary embodiment introduces a structure having a single abutment section, it is not limited thereto. Forming a plurality of abutment sections 231 allows discharge reed 226 to have more preferable springiness in opening movement and reaction force. This provides a hermetic compressor having further less excessive compression and high refrigeration performance, that is, having further high energy-efficiency.

After abutting against abutment section 231 of stopper 227, discharge reed 226 further bends and reaches restraint section 232. Because discharge reed 226 contacts with restraint section 232 with a section close to the tip, discharge reed 226 is unlikely to have further bend. This can suppress internal stress in discharge reed 226 due to the deformation. Even under condition where a large deformation is expected in discharge reed 226 due to liquid compression or compression of highly concentrated refrigerant gas, an excessive increase in the internal stress in discharge reed 226 is prevented. This protects discharge reed 226 from breakage, providing the structure with high reliability.

Stopper 227 and head 216 are integrally molded by die casting. Abutment section 231 and restraint section 232 are formed in the same mold, that is, dimensional accuracy in the mold directly affects the height of abutment section 231 and restraint section 232. A mold is delicately manufactured so as to have tolerances of several ten micrometers or smaller, which therefore allows abutment section 231 and restraint section 232 to have surfaces with high dimensional accuracy with no additional finishing process. The structural advantage above contributes to high productivity and reliable quality.

According to the structure of the second embodiment, cap 233 is made of fluorine resin such as tetrafluoroethylene.

Tetrafluoroethylene is non-adhesive and has extremely high solid lubricity. By virtue of the property, when discharge reed 226 rubs on cap 233, the touched surfaces smoothly slide with each other, thereby protecting discharge reed 226 from wear caused by metal-to-metal abutment against stopper 227.

Besides, because of the non-adhesive property of tetrafluoroethylene, discharge reed 226 is easily away from stopper 227 after abutment. This contributes to a quick closing movement with no delay of discharge reed 226, thereby enhancing refrigeration performance of the hermetic compressor. In addition to the advantage above, tetrafluoroethylene has high periodic damping capacity and elasticity. This eases the shock occurred at the abutment between discharge reed 226 and stopper 227, and suppresses an impulsive sound produced in the abutment, thereby protecting discharge reed 226 from damage caused by the shock. As a result, a highly reliable, noiseless hermetic compressor can be obtained.

Such a simple assembly—where cap 233, which is formed of fluorine resin in advance, is press-fitted with stopper 227—enhances the productivity.

Although cap 233 is formed of tetrafluoroethylene in the embodiment, it is not limited thereto. The same effect can be obtained by employing similar resin material, such as polybutylene naphthalate, polybutylene terephthalate, polyphenylene sulfide.

INDUSTRIAL APPLICABILITY

The structure of the present invention, as described above, provides the hermetic compressor obtained an improvement in the closing movement of the discharge reed and therefore in energy efficiency. The hermetic compressor is applicable to an air conditioner and a refrigerating and air-conditioning device. 

1. A hermetic compressor comprising: a cylinder in which a piston has a reciprocal movement; a valve plate that seals an opening end of the cylinder and has a discharge valve unit on a side opposite to the cylinder, and a head having a discharge chamber for accommodating the discharge valve unit, the discharge valve unit further including: a discharge hole disposed on the valve plate so as to have communication with an inside of the cylinder; a valve seat section formed outside the discharge hole; a discharge reed that is made of leaf spring material and contains an opening/closing section for opening and closing the discharge hole and an arm section; and a stopper for restraining opening of the discharge reed, the stopper further including: an abutment section disposed at a position corresponding to the arm section so as to keep a clearance from the arm section.
 2. The hermetic compressor of claim 1, wherein the stopper contains a restraint section that has a clearance at a position corresponding to the opening/closing section so as to be greater than the clearance of the abutment section.
 3. The hermetic compressor of claim 1, wherein the discharge reed and the stopper are fixed to the valve plate.
 4. The hermetic compressor of claim 1, wherein the stopper is molded on the head.
 5. The hermetic compressor of claim 2, wherein abutment surfaces of the abutment section and the restraint section are made of a solid lubricating material.
 6. The hermetic compressor of claim 2, wherein the discharge reed and the stopper are fixed to the valve plate.
 7. The hermetic compressor of claim 2, wherein the stopper is molded on the head. 